Warning: this is wild speculation by somebody who doesn't know what he's talking about. But often that's where the best ideas come from.

As far as I understand it, current methods of cloning involve removing the DNA from a relatively mature cell and injecting it into a primed egg cell that has had
its own DNA removed. This process often damages the DNA, if not the cell, in ways that may not be discovered for 20 years.

It occurs to me that viruses are much better at this. They wrap their genes (usually RNA) in a well-built protective coat along with the mechanism to transcribe it into the host cell's DNA.

Rather than removing the DNA from the original cell by hand, why not create a virus-like transporter. This is in several stages:

1. The wrapper module is somewhere between a virus and a mitochondrion. Injected into a cell it doesn't write over the host cell's DNA. Instead it uses its own and the cell's machinery to make copies of the host DNA and build virus-like carriers.

2. The eraser module is simpler than a virus. Its job is to enter an egg and delete any DNA it finds. A virus would not naturally, as it would be suicide. Having done this, it would die (cease to function).

3. The carrier module is allowed to enter the target egg. Its job there is simply to release the DNA sack it carries and allow the egg to absorb it. No transcribing necessary.

The carrier module could quite possibly be created outside as well, in which case the wrapper simply has to make copies of the host DNA suitable for it to take up.

I do realise that a cell's DNA is many, many times larger than most viruses. However, a custom-built carrier component shouldn't be too hard to build, since it doesn't need to do the transcribing job of a virus.

First of all, current method of cloning involve transfering nucelus from a cell to another. Virus are simple gene replication machines. They don't even have DNA structures in them since DNA are self replication machine while a virus mirror replicate itself. If a virus can by pass normal cell defense and destory DNA of its host, it will be most lethal to all living things on earth. To ensure cloning, you will need a 99.9999% accurate DNA replication, which won't be possible if you replicate DNA piece by piece using carriers.

A rogue gamite senses its prey and moves close to the vulnerable ova, crowded on all sides and 99.9999% defenseless. Drawn in by a scent or by the nearly imiscible exudative aura of the ova, one brush to the ova is enough to ignite chemistry between the two. In a heartbeat, reactivity of the gamite with the ova's surface causes a crystallization of the membranous ova and a minor disintegration of the membrane at the point of contact with the gamite. An opportunist, the gamite burps its genetic core into the ova and collapses in to bridge the rended membranous anchor point. / This process often damages the DNA, if not the cell, in ways that may not be discovered for 20 years /

bing brought up a really good point. What if the virus mutated? What if it began producing toxins, or switched on oncogenes? Genetic recombinants are great fun to play with. It doesn't hurt anybody to make plants which secrete bt, for instance, because it's highly unlikely the genes involved could mutate so that the protein product became deadly to people. This, on the other hand, would be highly risky, especially since you're transferring human DNA, which has potentially very destructive genes in it already.
-Greg

Seems to me like we have very destructive genes turned on permanently... *duck*

The eraser component couldn't mutate because it has no genetic code to mutate with. It's just a machine, built from proteins - it erases, then it dies, without reproducing.

The carrier just carries the DNA it's given. Only the wrapper has any genetic code of its own.

Tell me, why is copying the DNA like that any more likely to mutate than ordinary cell division? It's division that happens inside the cell, using the cell's machinery.

This could even work without copying - simply get the carrier to swallow the nucleus of the original. Requires more precise positioning, rather than the safe 'hands off' approach I was aiming for, but it could still work.